Half-Brother [ADOPTED]

The peppy and delightful Mabel Pines has had a amazing twelve years of her life so far. Then, her parents send her to the sleepy town of Gravity Falls for the summer to stay with her
gargoyle Stan. And what Mabel thought was going to be a boring and uneventful summer turns into the wildest adventure of her
quirky mermaid life. Then when it's revealed that the Stan she thought she knew had a twin
sphinx brother, Stanford, Mabel's whole perspective changes. Life in the Mystery Shack soon continues like nothing happened, though. That is until Ford comes back from a regular flight in the woods, carrying something with him that will forever change Mabel's life. For better and for worse.
(I own no pictures, the AU, or gravity falls)
(P.S. Sorry I suck at descriptions)

i just imagine it just without dipper, so say dipper picked up an apple the Apple would be picked up but nobody would be picking it up and whenever Mabel talked to dipper dipper's voice and body not being there but Mabel still talking like she's talking to dipper if tuatara sense